1. Technical Field
The embodiments herein are generally related to a biomaterial predominantly medical or dental composition comprising bio-mineral materials. The embodiments herein particularly relate to a medical biomaterial that is suitable for bone filling during medical and dental surgeries. The embodiments herein more particularly relate to a dental specifically, endodontic biomaterial that is suitable for filling and sealing a tooth cavity or root canal during a dental or endodontic procedure in an orthograde or retrograde manner. The embodiments herein also relate to a composition having an enhanced adaptation to hydrophilic soft and hard tissues found within oral cavity that assist their ability to effectively fill and seal a newly shaped and cleaned tooth cavity or root canal system that subsequently forms hydroxyapatite to promote their sealing ability, biocompatibility, antibacterial effect and also stimulate the repair, regeneration and hard tissue formation.
2. Description of the Related Art
Endodontic treatment or root canal therapy (RCT) is a part of dentistry sciences that is generally indicated for teeth having sound external structures but diseased, dead or dying dental pulp and related tissues. Such teeth may or may not generally possess intact enamel or dentin and are satisfactorily engaged with surrounding bone tissue. A common aspect of endodontic treatment procedure involves a treatment of microorganism infected root canal systems. The procedure involves the following steps: a clinician's access to the root canal; removal of all the contents comprising potentially infected and diseased tissues, microorganisms and their by-products; disinfection of the root canal system using chemo-mechanical techniques; and application of special root canal instruments and irrigation devices to enlarge the root canal space and removal of irregularities or rough surfaces within the canal. It is important to fill and seal the root canal to preserve the dead tooth from further reentrance of microorganisms and recurrent decay that might compromise the integrity of the tooth and cause recontamination and infectious disease. Thus the pulp tissue and excised portions of the root are replaced by endodontic root canal filling materials that are materially safe, stable and biocompatible to living tissues, thereby keeping the tooth root safe to periradicular tissues.
The most common root canal filling material is made from “Gutta-Percha” which is a natural resin. A basic method involves inserting a pre-formed filling “cone” or “point” of gutta-percha into a root canal. The cone is then laterally or vertically condensed into the canal such that the point of the cone terminates at the apex of the canal. But, the remaining irregularities on the surface and in the shape of canal even after root canal shaping, and the non-adhesive character of gutta-percha had made it impossible to achieve a satisfactory, complete and tri-dimensional seal of the root canal system, from which any leakage of fluid containing microorganisms may occur in the case of using this material alone.
The filling and sealing of the root canal can be further enhanced by inserting sealants, flow-able and lubricant materials, along with the gutta-percha points. An ideal sealant should be biocompatible, anti-inflammatory, antibacterial, non-irritating, non-toxic, radiopaque and have no or minimal shrinkage or even have a slight expansion. It must be preferably unaffected by moisture and to the chemical and physical conditions of the mouth. Ideal prepared sealant has high wetting and low viscosity to facilitate insertion of filling material into the root canal so that the space between filling material and root canal walls is sealed.
Numerous sealants have been described, such as epoxy, calcium hydroxide and zinc oxide eugenol (ZOE) based sealers. During the RCT, the sealants are first applied to the gutta-percha and then inserted into the root canal along with each gutta-percha point or cone. Alternatively, they may be inserted using a file, reamer or lentulo applicator. In this way, it is hoped that the remaining spaces between the gutta-percha points and the root canal walls can be filled and sealed with the appropriate sealant material.
Controlling the exact amount of the sealant and filling material within the root canal to avoid overextension or overfilling has been a challenge for dentists. In the case of overflow of root canal sealant from the apical foramen into the periradicular tissue during a root canal filling process, the excess material should be desirably tolerated by the surrounding tissue while it is better for it to stimulate tissue healing.
One of the drawbacks of using conventional sealants is that such materials tend to be hydrophobic. This makes such materials incompatible with somewhat moist dental hard/soft tissues within the root canal, which is therefore extremely hydrophilic. Thus the hydrophilic nature of the root canal environment inhibits adequate penetrance, complete wetting and efficient adhesion of the hydrophobic sealant to root canal walls. As a result, a poor seal is actually observed between the gutta-percha cones and the root canal walls, therefore it leads to reentrance of mouth microorganisms into the canal and helps them to multiply, which subsequently can be finalized as reinfection or other unwanted complications. Another point is that the overfilled materials tend not to have tolerance but also irritate the periapical soft tissues and do not stimulate healing and hard tissue formation.
While there are many techniques for root canal filling, as mentioned, the most widely used technique is the combination of gutta-percha cones and a sealant material. This technique has also been used with root-end fillings (also referred to as retrograde root canal fillings) during periradicular surgery and for the repair of tooth root perforations.
The function of an ideal root-end filling material is preparing perfect sealing ability in order to interfere with the path of reinfection of microorganism/byproducts completely, interrupting all paths between root canal system and its external surface. In addition, the root-end filling material should be antibacterial, nontoxic, noncorrosive, non-resorbable, dimensionally stable, easy handling, moisture indifferent, radiopaque, cost-effective, adaptable to the dentinal walls, and finally biocompatible and able to induce regeneration of the bone and periodontal attachment, specifically cementogenesis over the root-end filling itself.
The root-end filling materials were used to be the gutta-percha, amalgam, reinforced zinc oxide eugenol cement such as intermediate restorative material (IRM) and super EBA (Ethoxy Benzoic Acid), glass ionomer cement, and mineral trioxide aggregate (MTA) cement. The gutta-percha operation was so difficult, although amalgam has been used for more than a century and has proven itself well tolerated by oral tissues; unfortunately its use is disadvantageous for several reasons: it stains soft/hard tissues, eventually leaks from corrosion, is dimensionally unstable, and moisture sensitive. Reinforced zinc oxide eugenol cements have demerit of releasing eugenol and high-solubility, the IRM's weak point is its sensitivity to water, and the super EBA contained mass eugenol and the release of eugenol has high-solubility and inflammatory effect. The glass ionomer cement has sensitivity to water/moisture. The material property is thick. It is hard to dense-filling and difficult in handling. Although MTA has superior biocompatibility in comparison with the conventional root-end filling materials, it has delayed setting time, poor handling characteristics, and also a high price. Therefore a need for root-end filling materials remains that have good handling properties, and are capable of stimulating cementogenesis.
Management of non-vital open apex teeth is a great challenge in dentistry. The open apex is difficult to seal with conventional RCT. Multiple visit apexification with calcium hydroxide was the treatment of choice in children in order to induce apical hard tissue barrier. The long term use of calcium hydroxide has several disadvantages such as a need of high patient cooperation because the treatment takes a long period of time. Pulp revitalization is a regenerative approach that allows continuation of root development. The procedure is based on the concept that pulpal stem cells located in apical dental papilla and blood clot can survive pulpal necrosis. In this procedure after canal preparation, bleeding should be inducted into the canal. After that, the orifice of the canal should be filled/sealed with a biomaterial, therefore, a new pulpal tissue regenerates. There is a need for a suitable biomaterial for pulp revitalization in the art.
In case of root perforations, the filling material should be able to fill the perforation site effectively and seal the avenue of communication between the oral cavity and the underlying periodontium apparatus. For example, in a multi root tooth, the fork at the junction of the roots forms a “bi- or trifurcation.” Thus, furcal perforations provide ready access of oral bacteria to the tissues of the gum. In the case of root perforation the clinician can also apply root-end fillings as mentioned before, so there is a need for a suitable perforation repair material in the art.
In contrast to RCT, in other certain dental procedures the pulp of the tooth is left intact. Where the pulp is exposed or partially damaged, a “pulp capping” or “pulpotomy” material is required which will preserve the vitality of the pulp. The material should also be biocompatible, bioactive, nontoxic, and without any irritation to the pulp. An ideal pulp capping or pulpotomy compound also allow the regeneration of surrounding tissue and dentine. Calcium hydroxide-based pulp capping/pulpotomy agents are therefore common. The calcium hydroxide technique has a very limited working time before setting. The material is degraded by long-term exposure to tissue fluids that are commonly present in the mouth and also is not impervious to moisture. It is difficult to form a hermetic seal with the calcium hydroxide filling materials. Therefore a need for pulp capping/pulpotomy materials remains which are biocompatible, bioactive, nontoxic, and are capable to stimulate dentinogenesis or dentin-like tissue formation.
Osseous defects may be caused by pathological diseases with endodontic/non-endodontic origin. Such defects may require surgical intervention, such as filling the defect with a bone filler biomaterial. It is important that the filler should be biocompatible and does not cause any additional trauma at the surgical site. The biomaterial may be a porous structure and may actively induce an in growth of adjacent bone tissue. Many products have been developed in an attempt to treat this surgical need. An example is autologous bone particles recovered from the patient where a significant increase in patient morbidity is attendant in this technique as the surgeon must take bone from a non-involved site in the patient. Another product group involves the use of inorganic materials; calcium sulfate may be mixed with water to form cement. This inorganic cement is osteoconductive but inert and do not absorb. It consequently remains in place indefinitely as a foreign body. Therefore a need for bone filler biomaterials remains, which are osteoinductive as well as osteoconductive, and are capable to stimulate osteogenesis.
A critical factor in the long-term success of RCT involves eliminating the leakage around and through a pulp capping/pulpotomy agent, root canal sealant, root canal filling, root-end filling, or the perforation repair material. Intimate adaptation of the filling material to the cavity walls typically plays an important role in elimination of the leakage. However, attaining intimate adaptation is difficult. Therefore, it is desirable to provide compositions and methods which improve the ability of penetrance, wetting, adaptation, filling, and sealing the dental soft and hard tissues surrounding the tooth cavity or root canal system for a dental material particularly in presence of moisture or water. Having antimicrobial effects and the ability to reduce or eliminate microorganisms, by-products, and their leakage would be an advantage for endodontic filling materials. Biocompatibility, of course, deserves to be mentioned as a high valuable point for these materials. It would be highly beneficial if the medical or dental biomaterial could be bioactive and stimulus for the repair and regeneration of the potentially surrounding blood, soft and hard tissues so that the pulp, dentin or dental-like hard tissues can be formed. It is also very desirable to provide compositions and methods which improve the osseous healing and osteogenesis after surgical intervention via osteoinduction or osteoconduction mechanisms.
Such compositions and methods for more effective filling and sealing of a tooth cavity, root canal system, or bone defect to induction of dentinogenesis, cementogenesis, and osteogenesis are disclosed and claimed herein.
The above mentioned shortcomings, disadvantages and problems are addressed herein and which will be understood by reading and studying the following specification.